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Dyes are stable organic pollutants that have been used in many industries and become one of the toxic contaminants for the environment. This research aimed at preparing a magnetic chitosan nanocomposite (MCN) as an effective adsorbent for cationic and anionic dye removal from aqueous solution. The MCN was synthesized using a coprecipitation method. The physical properties of MCN were characterized using elemental analysis (CHNO), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray diffractometry (XRD). The results confirm that chitosan has been embedded on the surface of magnetic material and shows superparamagnetic properties behavior. A series of adsorption were conducted to investigate dosage of adsorbent, contact time and initial dye concentration to obtain the optimum condition of adsorption for both methylene blue (MB) and congo red (CR) dyes. The experimental equilibrium adsorption were then analyzed by the Langmuir and Freundlich isotherm models. Based on the correlation coefficient (R 2) values, the equilibrium adsorption data were fitted to the Langmuir isotherm model. The maximum adsorption capacity (q m) obtained from the Langmuir isotherm model for MB and CR onto MCN was 0.1308 and 1.8257 mg/g, respectively. Results highlight the potential of MCN application as an adsorbent for water contaminated by dyes.

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The study aimed at developing and evaluating a simple green electrochemistry experimental kit named Lectrofun 2.0. Lectrofun 2.0 is an educational kit equipped with a module built with the criteria of user-friendly, costeffective, and laboratory free. The basic concept of electrochemistry was introduced through a guided learning approach via the module. The objectives of this research were to (1) develop Lectrofun 2.0 module using green chemicals, recyclable and easily accessible materials and (2) evaluate the module effectiveness in terms of student achievement/understanding of the Electrochemistry topic. This is a Design and Development Research (DDR) using the ADDIE model as an instructional design model. The development phase involves the first objective of the study, while the evaluation phase involves the second objective. Total of 46 respondents of pre-post tests were involved in evaluating effectiveness of Lectrofun 2.0 in terms of student achievement/understanding of the topic. The findings showed that 73.9% of students from the treatment group showed 4-grade increment (from grade E to grade A). This study showed that Lectrofun 2.0 has a significant impact on enhancing learner comprehension of Electrochemistry topic, enjoyment in learning, and learning to care for the environment.